The invention relates generally to sensing and measuring equipment and methods, and particularly to a system for automatically scanning, mapping and reproducing the dimensions of three dimensional objects. In one specific aspect, the invention has application to dentistry, for scanning, mapping, and storing the three-dimensional topography of teeth, for dental restorations.
Various systems and methods have been suggested for three dimensional mapping or surface measuring of objects. Among these has been a system intended for dental applications and comprising a triangulating device with two cameras looking at each survey point from different angles. This system was very costly, and yet had a resolution of only about 200 microns.
Other systems in the general field of three dimensional mapping or topography measuring and recording have also made use of the conventional triangulation scheme wherein either two cameras have been aimed at a spot from different angles, thereby giving a relief measurement or distance from the cameras, or a narrow light beam has been projected at an area from one angle and a camera has recorded from another angle the position of the light beam, similarly giving the relief distance measurement. In some of these prior systems galvo scanners have been employed. The galvo scanners have required too much space to enable miniaturization as achieved by the present invention and as necessary for dental applications. Further, they tend to require a great number of calculations and thus a powerful computer.
None of the prior systems has been as simple, efficient, rugged and reliable, capable of relatively high precision, while also being small and compact to the extent of easily fitting as a probe into a dental patient's mouth, as is the apparatus and system of the present invention described below.